Charging system problems

[jhark37]

Hi, All,

Relatively new to the forum and the xs. Just completing a restoration of an 82 xs400 Seca. Starts and runs OK, although it will need a little carb tuning.

Problem is the charging system is not working. Have measured 4.9 ohms on the rotor and about 1.0 on
the 3 white field coil leads. Rotor is to spec, but field coil should be .5, if I rremember correctly. Anyway, get no voltage output from the generator. Test leads on battery with the engine running show just basic battery
voltage, not the 14 - 14.5 I'd expect. What do you all suggest as a next step?

Thanks, John

 

[NewHavenMike]

You should be getting 14-15v at a cruising RPM, above 3k. Ive installed a volt meter gauge on my bike so I know whats happening. Losing battery/charging power in the middle of the night is no fun, ask me how I know...

When I turn the headlight on, I loose 1 volt. It also depends on how charged the battery is and how long its been sitting. If I ride everyday, cruising voltage will be around 14-14.5v, remove one V if I use the lights. If the bike sits for a couple days, the volts will stay at 15v when cruising to charge.

 

[jhark37]

Thanks for taking the time to reply. But what I'm really looking for is what are the likely culprits? I can think of 4, maybe there are more. Regulator, brushes, rotor or stator. Suggestions as to most likely cause?

Thanks, John

 

[jhark37]

Like to revisit this issue. Have used "Curleys Troubleshooting Guide". Have also replaced the regulator with a brand new one. If I ground the green wire on the regulator connector, the charging system works. Get 14+ at the battery. Curley gives 2 possibilities, bad regulator or bad regulator ground. As I said,
regulator is brand new and black wire from regulator tests good for ground.

Where to now? Any ideas? Is it safe to leave the green wire grounded for a long term solution?

Thanks, John

 

[BBS360]

You'd be running the alternator at maximum output all the time. Could burn out the stator or field coil.
Would also be boiling your battery.

Which specific regulator did you buy?

 

[jhark37]

Bought regulator on Amazon, believe it or not. Listed specific part # for an
82 Seca 400. I suppose something could be wrong with it, but it would be hard
to believe! Wire colors are correct, fits the connector, etc.

 

[jhark37]

I know there has not been much interest in this thread, but thought I'd close the loop anyway. As I mentioned earlier, I had purchased
a new regulator with no change in the results. Hard to believe I had 2 nonfunctioning regulators. But true. Finally got a good one
and the system works. 14+ volts at the battery. I've also tried to reduce the load by using LED tail/brake lights as well as an LED
headlight. Like the look, too. Have finally finished the restoration and am VERY pleased with the result. What a great bike!

Cheers, John

 

[NewHavenMike]

I once bought a new "plug and play" rec/reg combo that plugged into the stock harness. I didnt work either. What a waste of $100.